As described in copending application Ser. No. 111,199 three-wheeled vehicles have long been used for automotive transportation. Their use has been limited because of the problem of instability, for which reason four-wheeled vehicles have become prevalent.
Certain specialized three-wheeled vehicles are used today such as golf carts and delivery and other small utility vehicles, as well as three-wheeled motorcycles used as sport vehicles. To increase stability, these vehicles are generally built with a low center of gravity. This is accomplished by the use of small wheels and the placement of passenger seating in a relatively low position.
In the United States, Federal and local laws place minimums on the diameter of wheels and on the distance of the seat from the ground. This limits the degree of stability possible in the design of three-wheeled vehicles. As a result, many commercially made three-wheeled automobile vehicles manufactured in this country and in others are not legally usable on roads in the U.S. Although many of these are made in and used in Europe, they are not imported into the U.S. Those made here are relegated to "off road" use, or use by governmental agencies, such as police, which are permitted to use vehicles which do not conform to these regulations. Three-wheeled motorcycles are generally used by experienced sport motorcycle drivers rather than the average citizen.
Three-wheeled automotive vehicles pose an additional problem owing to their small size relative to the size of the other cars on the roads they share. This is that the driver and passengers do not feel safe or confident unless they are seated relatively high off the road. To be seated low in traffic consisting of conventional cars results in an insecure feeling, deriving most likely from lack of visibility on the part of the driver and the knowledge that he is not conspicuous to other drivers. The achievement of stability in three-wheeled vehicles by the use of low seating and/or small wheels is limited by the regulatory laws mentioned above and by the need for the feeling of height on the part of the passengers and driver.
The need to provide a covering for the passengers as protection against the weather complicates the problem as a structure above the heads of the passengers will tend to elevate the center of gravity by adding weight at a relatively high point.
The use of electric storage batteries introduces a further problem, that of providing sufficient energy storage capacity to offer enough range of driving between recharges of the batteries commensurate with practical needs. Numerous electric vehicles exist today. They consist of full-sized, four-wheeled electric automobiles weighing thousands of pounds, as well as smaller three-wheeled vehicles used as off-road utility vehicles of golf carts. Even these tend to weigh upward of several thousand pounds. None of these vehicles are for general road travel and regular transportation due to their general impracticality concerning range, cost, utility, and stability. These problems arise from the need to supply energy storage capacity sufficient to move the weight of the vehicle and its load by means of electric storage batteries which themselves are so heavy as to contribute substantially to the load. They also require heavier chassis construction merely to support them.
French Pat. No. 1,142,921 and the Michael U.S. Pat. No. 3,284,130 show windshields with the Michael patent further showing what might be regarded as constituting a canopy. Specifically, the Michael patent discloses a windshield and spray shield construction which comprises an upright windshield frame with devices securing the frame to an upper portion of the front end of the main frame of a motorcycle. The construction also includes devices defining a pair of support arms projecting rearwardly and downwardly from opposite side portions of the lower end portion of the windshield frame. The main frame of the motorcycle includes forwardly and upwardly inclined forward portions from whose upper end the front wheel assembly is pivotably supported. An upstanding flexible spray shield is secured between the aforesaid arms and is passed over the forwardly and upwardly inclined portion of the main frame. The support arms generally parallel the forwardly and upwardly inclined portion of the main frame and are disposed forwardly of the upwardly inclined position.
The prior art fails to reveal a three-wheeled lightweight vehicle with an advantageously positioned center of gravity as is provided in accordance with the invention and as will be discussed in greater detail hereinafter.